19.A representative must subordinate his personal interests to those of his client or any potential client. Without limiting the generality of the foregoing, the representative:
(1) may not advise a client to invest in a legal person, partnership or property in which he has, directly or indirectly, a significant interest;
(2) may not conduct any transaction or enter into any agreement or contract whatsoever with a client who, manifestly, is unable to manage his affairs, unless the decisions to conduct these transactions or enter into these agreements or contracts are made by persons who may legally decide in lieu of this client;
(3) may not conduct any transaction or enter into any agreement or contract whatsoever in the capacity of representative with respect to a client for whom he acts as dative tutor, curator or adviser within the meaning of the Civil Code.